Micro-miniature coaxial cable connector and receptacle assemblies are used in the telecommunications industry because of their very small size and light weight. Typically, the receptacle is surface mounted to a circuit board in a cellular telephone, pager, or other portable communications device that is carried by a person. The purpose of the micro-miniature connector and receptacle assembly is to easily interconnect certain components with circuitry on the circuit board and to provide a means for disconnecting them for maintenance of replacement. An example of such a cable connector assembly is disclosed in U.S. Pat. No. 5,110,308 which issued May 5, 1992 to Nishikawa et al. Since these communications devices are generally hand held units, they are sometimes subjected to somewhat rough handling which may cause the cable connector to disengage from its mating receptacle. When this occurs, of course, the unit is disabled. It is, therefore, desirable to provide means for locking the two parts together. This may be accomplished by increasing the interference between the two mating parts, as is done with the connector disclosed in U.S. Pat. No. 5,180,315 which issued Jan. 19, 1993 to Nagashima. A coaxial cable connector is utilized in the '315 patent and has an outer shell contact that includes a segmented annular rib that resiliently engages a recess in the mating receptacle contact, thereby holding the two parts together by friction. When separating the two parts, the segmented annular rib is elastically deflected outwardly away from the groove. This, however, increases the amount of force that is necessary to disconnect the cable connector from the receptacle. When sufficient friction is achieved to prevent inadvertent unmating of the cable connector from the receptacle, the force required to disconnect is so great that the solder connections between the receptacle and the circuit board may be compromised, and the receptacle may even be pulled from the circuit board. Other types of latching mechanisms that may be incorporated into the housings of the two mating parts require a substantial amount of space, usually in the form of thicker housing walls that translate into a larger mounting foot print. This is an obvious disadvantage in the present application where the physical size of the cable connector and mating receptacle must be minimized. Such micro-miniature connector and receptacle assemblies must, by necessity, be kept small. For example, for a coaxial cable having an outside diameter of about 0.070 inch, the corresponding cable plug connector would have a nominal diameter of about 0.120 inch and the mating receptacle would have a width of about 0.215 inch and a height of about 0.145 inch. Note that these dimensions include the insulating housings and the mating contacts for both the ground and signal conductors in the coaxial cable. There is little room for an integral latching mechanism.
What is needed is a micro-miniature coaxial cable connector and surface mount receptacle assembly that has a positive locking mechanism for holding the cable connector in engagement with the receptacle without increasing the force needed to separate the connector assembly and without increasing the amount of space required for mounting on a circuit board.